Viral or bacterial infections may cause diarrhea and vomiting, but these symptoms can also occur with other health conditions, like anxiety and parasites.

Though a virus is usually the culprit, certain medical conditions and side effects of medications can also lead to vomiting and diarrhea at the same time.

Vomiting and diarrhea can happen for a number of reasons.

A stomach virus or bacterial gastrointestinal (GI) infection is the most likely cause in children, but these infections can also affect adults.

A number of other reasons exist for these symptoms, such as drinking too much alcohol. Often, vomiting and diarrhea occur together with fever, but not always.

Here are the most common causes of simultaneous vomiting and diarrhea symptoms, with and without fever:

Viral gastroenteritis

Viral gastroenteritis is an intestinal infection and it’s often referred to as the stomach flu. It is, however, unrelated to influenza (the flu) since it is caused by different viruses.

Common causes of gastroenteritis include:

While all of these viruses can affect people of any age, the latter three are most common in infants and toddlers.

These viruses are transmitted from person to person by contact with infected stool and vomit. This can happen when a person with the infection doesn’t wash their hands thoroughly after using the restroom and then touches objects or prepares food for others.

In addition to vomiting and watery diarrhea, symptoms of viral gastroenteritis include:

Food poisoning

Food poisoning is an infection of the GI tract often caused by bacteria, parasites, or viruses.

You can get food poisoning by eating contaminated food. This can happen at home or in restaurants when food is handled incorrectly or not cooked properly.

Several bacteria can cause food poisoning, including:

Symptoms of food poisoning can start within hours of eating and often resolve within a few hours or days. Unless symptoms are severe, this usually happens without medical treatment.

Vomiting and watery diarrhea are the most common symptoms of food poisoning. Other symptoms include:

Traveler’s diarrhea

Traveler’s diarrhea is a digestive tract disorder that’s most often caused by viruses, parasites, or bacteria in water or food. It’s most likely to occur when you’re visiting an area with a different climate or sanitation practices than what you’re accustomed to at home.

Traveler’s diarrhea generally clears up within a week. Watery diarrhea and cramps are the most common symptoms, but traveler’s diarrhea can also cause:

You can check the Centers for Disease Control and Prevention (CDC) website to see if there is a health notice for the regions to which you recently traveled.

Stress or anxiety

Gastrointestinal function may be influenced by the stress response. In fact, stress and anxiety commonly cause a number of gastrointestinal symptoms, including:

Stress hormones slow motility, or movement, in the stomach and small intestine. They also trigger an increase in motility in the large intestine, leading to some of these symptoms.

Stress and anxiety have also been linked to the development and worsening of symptoms of irritable bowel syndrome (IBS) as well as inflammatory bowel disease (IBD).

Pregnancy

The body goes through numerous changes during pregnancy. Morning sickness is the most common cause of vomiting in pregnancy. Despite its name, morning sickness can occur at any time of the day.

Some people develop hyperemesis gravidarum, a condition that causes severe nausea and vomiting during pregnancy.

Vomiting and diarrhea in pregnancy can also be caused by hormonal changes, new food sensitivities, and dietary changes. Prenatal vitamins also cause diarrhea in some people.

Gastroenteritis, common during pregnancy, may also cause these symptoms.

Overeating or overdrinking

Overindulging in food or drink can cause vomiting and diarrhea at the same time along with:

The type of food you eat also matters. Eating large amounts of greasy or sugary foods may irritate your stomach and cause vomiting and diarrhea at the same time within hours.

Overeating is even more likely to cause these symptoms if you already have a gastrointestinal condition, such as IBS, stomach ulcers, acid reflux, or gastroesophageal reflux disease (GERD).

The relationship between alcohol and the gut is complex. Some types of alcohol, including sugary alcoholic drinks, can cause diarrhea by inducing a quicker gut transit time. This decreases digestion, as the gut doesn’t have time to absorb the nutrients or other substances that are rapidly passing through it.

High alcohol use can cause a condition known as alcoholic gastritis, which is an irritation of the stomach lining. Acute gastritis can occur after drinking high amounts of alcohol quickly, or gastritis can become chronic in people who drink alcohol regularly.

Gastritis may cause symptoms like:

Symptoms may improve or worsen after eating, depending on the food you eat.

Medications

Vomiting and diarrhea are potential side effects of many medications. This may be related to the way the medication works or because it contains additives that irritate the stomach.

Your age, overall health, and other medications you take can also increase the chance of side effects.

Medications that commonly cause vomiting and diarrhea at the same time include:

One way antibiotics can cause vomiting and diarrhea is by killing the “good” bacteria that live in your GI tract. This allows bacteria called Clostridioides difficile to become overgrown, which can result in symptoms similar to severe food poisoning.

Taking medication with food can sometimes relieve symptoms. You can speak with a doctor about the best way to take your medication and reduce the chance of side effects.

Dehydration is a complication of vomiting and diarrhea, and it occurs when the body loses too much fluid. Dehydration can prevent your cells, tissues, and organs from functioning properly, leading to serious health challenges, including shock and even death.

Mild dehydration can be treated at home, but severe dehydration requires emergency care in a hospital.

Symptoms of dehydration in babies, toddlers, and children include:

  • persistent thirst
  • urinating less than usual, or going 3 or more hours without a wet diaper
  • dry mouth
  • sunken eyes or cheeks
  • decreased skin turgor, or elasticity
  • lack of energy
  • no tears when crying

Symptoms in adults include:

Vomiting and diarrhea usually resolve within a few days without treatment. Home remedies and medications can help you manage your symptoms and avoid dehydration.

Home remedies

Here are some ways you can treat vomiting and diarrhea at home to avoid dehydration:

  • Get plenty of rest.
  • Avoid stress.
  • Wash your hands with soap and water frequently.
  • Drink lots of clear fluids like water, broth, clear sodas, and sports drinks.
  • Eat saltine crackers.
  • Follow the BRAT diet, which consists of bland foods. BRAT stands for bananas, rice, applesauce, and toast.
  • Avoid foods that are greasy, spicy, or high in fat and sugar.
  • Avoid dairy.
  • Avoid caffeine.
  • Avoid alcohol.

Follow this advice if you have babies or toddlers:

  • Give your baby smaller feedings more often if needed.
  • Give sips of water between formula or solid food.
  • Give them an oral rehydration solution, such as Pedialyte.

If your child is vomiting and has diarrhea for more than 2 days, it’s important to consult a medical professional.

Medications and remedies

There are over-the-counter (OTC) and prescription medications available for vomiting and diarrhea. While generally safe for adults, OTC medications should not be taken without first consulting a doctor.

OTC medications include:

Do not give these medications to a child.

Ginger tea or chews may also relieve nausea and vomiting. These may not be indicated for children under age 2 and should be used in moderation and after consulting with a healthcare professional in children ages 3 and older.

A doctor may recommend antibiotics to treat vomiting and diarrhea in adults caused by bacterial infections, such as food poisoning.

When you’re experiencing vomiting and diarrhea, your aim should be to get some sustenance and avoid dehydration.

If an infection like gastroenteritis is causing your symptoms, start by trying home remedies. In other cases, professional medical care may be required.

For children

Take a child to the doctor if they:

  • are vomiting for more than 2 days or have diarrhea for more than 4 days
  • are unable to keep fluid down
  • are under 3 months old with a rectal temperature of 100.4°F (38°C)
  • are 3 months to 3 years old with a temperature of 102.2°F (39°C)
  • are under 5 years old and appear to have symptoms of dehydration, such as:
    • dry mucous membranes

It’s especially important to contact a doctor about possible dehydration if the child is too young to describe their own symptoms.

When to go to the emergency room

Take a child to the emergency room as soon as you notice symptoms if they:

For adults

See a doctor if:

Most of the time, vomiting and diarrhea at the same time are due to a stomach bug or food poisoning and clear up on their own within a few days. Getting plenty of fluids and eating a bland diet can help.

Keep an eye out for signs of dehydration, especially in infants and toddlers who are unable to communicate how they feel. Talk with a doctor if you or your child have severe symptoms or symptoms that last more than a few days.